1. Field of the Invention
The present invention relates to a vehicle steering system including a sensor that detects a vibration of a vehicle wheel of a vehicle.
2. Description of Related Art
In vehicle steering systems in related art, multiple sampling of a vibration level of a vehicle wheel during one rotation of the vehicle wheel is repeated over multiple rotations of the wheel, and thus, the vibration level of the vehicle wheel over multiple rotations of the vehicle wheel is detected. In the vehicle steering system, a vibration level sum value at each sampling position is calculated by summing the vibration level at the sampling position during each number of rotations of the vehicle wheel. In the vehicle steering system, a sampling position, at which the vibration level sum value exceeds a predetermined value, is determined, that is, a vehicle wheel region, in which the vehicle wheel is abnormal, is determined. Japanese Patent Application Publication No. 2009-184627 describes an example of the vehicle steering system in the related art.
In the vehicle steering systems in the related art, it is possible to determine a region of a vehicle wheel, in which abnormality occurs, but it is difficult to determine whether the abnormality is attributable to a tire of the vehicle wheel being punctured or burst.